Activated base metal catalysts

ABSTRACT

Nitro-compounds are hydrogenated with an activated Ni catalyst that has an average particle size (APS) less than 25 μm and is doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pt, Cu, Ag, Au and Bi via its/their addition to the alloy before activation and/or doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Cu, Ag, Au and Bi by their adsorption onto the surface of the activated catalyst. This invention also includes the hydrogenation of nitro-compounds with an activated Ni catalyst that has and APS less than 20 μm and is doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Tr, Pt, Pd, Mo, Cu, Ag, Au and Bi via its/their addition to the alloy before activation and/or doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Cu, Pd, Pt, Mo, Ag, Au and Bi by their adsorption onto the surface of the activated catalyst.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is US national stage of international application PCT/EP2007/055184, which had an international filing date of May 29, 2007, and which was published in English under PCT Article 21(2) on Dec. 4, 2008.

The invention concerns an activated base metal catalyst, and its use for the hydrogenation of nitro-compounds.

Activated metal catalysts are also known in the fields of chemistry and chemical engineering as Raney-type, sponge and/or skeletal catalysts. They are used, largely in powder form, for a large number of hydrogenation, dehydrogenation, isomerization, reductive amination, reductive alkylation and hydration reactions of organic compounds. These powdered catalysts are prepared from an alloy of one or more catalytically-active metals, also referred to herein as the catalyst metals, with a further alloying component which is soluble in alkalis. Mainly nickel, cobalt, copper, iron or combinations thereof are used as catalyst metals. Aluminum is generally used as the alloying component which is soluble in alkalis, but other components may also be used, in particular zinc and silicon or mixtures of these either with or without aluminum.

These so-called Raney alloys are generally prepared by the ingot casting process. In that process a mixture of the catalyst metal and, for example, aluminum is first melted and casted into ingots.

Typical alloy batches on a production scale amount to about ten to a couple hundred kg per ingot. According to DE 21 59 736 cooling times of up to two hours were obtained for this method. This corresponds to an average rate of cooling of about 0.2 K/s. In contrast to this, rates of 10² to 10⁶ K/s and higher are achieved in processes where rapid cooling is applied (for example an atomizing process). The rate of cooling is affected in particular by the particle size and the cooling medium (see Materials Science and Technology edited by R. W. Chan, P. Haasen, E. J. Kramer, Vol. 15, Processing of Metals and Alloys, 1991, VCH-Verlag Weinheim, pages 57 to 110). A process of this type is used in EP 0 437 788 B 1 in order to prepare a Raney alloy powder. In that process the molten alloy at a temperature of 5 to 500° C. above its melting point is atomized and cooled using water and/or a gas.

To prepare a powder catalyst, the Raney alloy which can be made by a known process (i.e. according to EP 0 437 788 B1) is first finely milled, if it has not been produced in the desired powder form during preparation. Then the aluminum is partly (and if need be, totally) removed by extraction with alkalis such as, for example, caustic soda solution (other bases such as KOH are also suitable) to activate the alloy powder. These types of catalysts can be activated with most bases and acids to give varying results. Following extraction of the aluminum, the remaining catalytic power has a high specific surface area (BET), between 5 and 150 m²/g, and is rich in active hydrogen. The activated catalyst powder is pyrophoric and stored under water or organic solvents or is embedded in organic compounds (e.g., distearylamine) which are solid at room temperature.

U.S. Pat. No. 6,423,872 describes the use of Ni catalysts that contain less than 5.5 wt % Al for the hydrogenation of nitrated aromatics. It describes the use of both commercially available standard activated Ni catalysts and supported Ni catalysts for the hydrogenation of nitrated aromatics, where problematic nickel aluminates are formed during this hydrogenation if their Al content is 5.5 wt % Al or higher.

These nickel aluminates can be in the form of takovite and/or takovite-like compounds and all of these nickel aluminates need to be removed from the desired amine before it is processed further. These nickel aluminates tend to form solids in the reactor and in the peripheral equipment (e.g., piping, settling tanks, filtration equipment, pumps and other equipment used in this process) that can deposit on their walls to decrease their heat transfer efficiency and to create blockages in the system.

Hence the formation of these nickel aluminates creates both safety hazards and a drop in productivity. The buildup of these nickel aluminates make it difficult to continue with the reaction and in such cases, one needs to shutdown the plant and clean out these deposits from the reactor and the peripheral equipment.

U.S. Pat. No. 6,423,872 also mentions the use of very specific alloy dopants limited to a definite list of elements that remain in the activated Ni catalyst after activation with caustic and the use of these resulting catalysts for the continuous hydrogenation of nitrated aromatics.

The conventional alloy doping elements from the groups IVA, VA, VIA and VIII of the periodic table of elements were specifically claimed in this patent. Additional Alloy doping elements such as titanium iron and chromium were also claimed.

U.S. Pat. No. 6,423,872 describes the use of a Ni catalyst having less than 5.5 wt % Al for the continuous hydrogenation of nitrated aromatics due to its lower formation of undesirable nickel aluminates during this hydrogenation. In principle, the less Al you have in the catalyst, the lower the amount of the nickel aluminates you will form. However these catalysts still form nickel aluminates and this technology does have its limits since the Al that is present in them is still considerably leachable under the conditions used for the hydrogenation of nitro-compounds such as nitrated aromatics.

U.S. Pat. No. 6,423,872 keeps the Al level lower than 5.5 wt % by changing the Al content of the alloy and/or increasing the intensity of the activation process. Increasing the Al content in the alloy will increase the amounts of Al-rich and more readily leachable phases such as NiAl₃ and the Al-eutectic phases. Another way to increase the amounts of these phases would be to perform the appropriate heat treatment to the alloy either after or during its production. Increasing the amounts of these readily leachable phases can also decrease the mechanical stability of these catalysts, thereby leading to a lower lifetime for the catalysts.

Hence lowering the Al content of the catalyst simply by increasing the amount of leachable phases in the precursor alloy does have its limitations.

Another method that U.S. Pat. No. 6,423,872 describes to decrease the Al content in the catalyst was to increase the intensity of the activation process by increasing the leaching temperature, pressure and other parameters that accelerate this process. However, not only does this increase the cost of the catalyst, but it also produces a sodium aluminate side product that is not salable and would need to be disposed of. Moreover if one is not careful during leaching, the newly formed sodium aluminate under these harsher conditions may deposit back on to the catalyst and block its catalytically active surface leading to lower activity and shorter catalyst life.

While the methods of U.S. Pat. No. 6,423,872 do decrease the level of leachable Al to some degree, they do not entirely solve the problems involved with the hydrogen of nitro-compounds, since most alloy activations used in catalyst production occur under different conditions than those of the continuous hydrogenation of nitro-compounds such as nitrated aromatic compounds. Thus the commercially applicable methods of U.S. Pat. No. 6,423,872 produce a catalyst that still has a considerable amount of Al in the catalyst that can be leached out during the hydrogenation of nitrated aromatic compounds.

Hence it is a goal of the present invention to produce a catalyst that generates lower levels of nickel aluminates buy minimizing the leachability of the remaining Al in the catalyst, regardless of the level of Al.

Surprisingly this problem is solved with the activated Ni catalysts according to this invention.

The formation of takovite during the hydrogenation of nitro-compounds with an activated Ni catalyst can be greatly reduced, or even eliminated, by doping the Ni/Al alloy with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pt, Cu, Ag, Au and Bi before activation while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred activated Ni catalyst formulation from this embodiment would be from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Fe, Ru, Co, Ir, Pt, Cu and Ag before activation while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

One can also greatly reduce takovite formation during the hydrogenation of nitro-compounds by doping an activated Ni catalyst that has an APS less than 25 μm with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred activated Ni catalyst formulation from this embodiment would be one that has an APS less than 25 μm and is doped by one or more elements from the list of Mg, Ti, V, Cr, Fe, Ru, Co, Ir, Ni, Cu and Ag by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

Another way to reduce takovite formation during nitro-compound hydrogenation is to use an activated Ni catalyst whose Ni/Al alloy was doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi before activation followed by doping the final activated Ni catalyst with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred activated Ni catalyst formulation from this embodiment would be from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Pd, Pt, Cu and Ag before activation followed by doping the final activated Ni catalyst with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Ni, Pd, Pt, Cu and Ag by its/their adsorption onto the surface of the catalyst while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

Takovite formation during the hydrogenation of nitro-compounds with an activated Ni catalyst can also be reduced greatly, by doping the Ni/Al alloy with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi before activation while keeping the average particle size (APS) of the final activated catalyst less than 20 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred activated Ni catalyst formulation from this embodiment would be from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Pd, Pt, Cu and Ag before activation while keeping the average particle size (APS) of the final activated catalyst less than 20 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

Lowering the level of takovite formation during the hydrogenation of nitro-compounds with activated Ni catalysts can also be achieved by doping an activated Ni catalyst that has an APS less than 20 μm with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred activated Ni catalyst formulation from this embodiment would be one that has an APS less than 20 μm and is doped by one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Ni, Pd, Pt, Cu and Ag by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

One method used for the doping of the catalysts of this invention involves the addition of the doping element(s) to the Ni/Al alloy prior to activation. Another doping method for the catalysts of this invention uses the adsorption of one or more elements either during and/or after activation and the post activation adsorption of the doping element(s) can be done before, during and/or after washing the catalyst. It is also possible that a washing step may not be needed at all. The adsorption of the doping element(s) can take place with existing compounds of the doping element(s) and/or with compounds of the doping element(s) that are formed in-situ during the doping process. The adsorption of the doping element(s) normally takes place in a liquid phase and the compounds of the doping elements can be soluble in the liquid medium or only slightly soluble in the liquid phase so that the rate of doping can be controlled by the solubility controlled concentration of the doping element(s) in the slurry phase. One could also add inhibitors (e.g., chelating agents), accelerators (e.g., precipitating agents) and combinations thereof that control the rate of adsorption of the doping element(s) on to the catalytic surface. One could also use the gas phase to adsorb doping elements provided that care is taken to prevent the excessive oxidation and deactivation of the catalyst. In such cases, it could actually be possible to adsorb the promoting elements via techniques such as evaporation, sublimation and sputtering onto the catalytic surface. This use of adsorption methods for the doping of the catalyst is clearly different than the addition of the doping elements to the alloy prior to activation in that the adsorption method concentrates the doping element onto the surface of the catalyst with very little, if any of it at all, being in the bulk of the catalyst particle.

The catalysts of this invention can also be doped by adding one or more doping elements to the Ni/Al alloy before activation followed by the addition of one or more doping elements via its/their adsorption to the surface of the catalyst. Clearly adsorbing one or more doping elements onto the surface of a catalyst whose precursor alloy contained one of more doping elements prior to activation will create a different type of catalyst than one that only used the alloy or adsorption methods of doping.

The doping level of the above mentioned catalysts can range from 0.01 wt % to 10 wt % for each doping element and the Al content ranges from 0.05 wt % to 10 wt %.

Optimally the catalysts can contain between 0.01 and 1.9 wt.-% Fe.

Optimally the catalysts can contain between 0.01 and 2.4 wt.-% Cr.

Optimally the catalysts can contain between 0.01 and 1.9 wt.-% Fe and contain between 0.01 and 2.4 wt.-% Cr.

The current state of the art for the hydrogenation of nitro-compounds typically uses an activated Ni catalyst that may or may not be doped with Cr and/or Fe, and it always has an average particle size (APS) higher than 25 μm, because of the higher catalyst manufacturing costs associated with this finer particle size distribution (PSD) and the issues dealing with catalyst separation from the product mixture. Surprisingly, if one produces an activated Ni catalyst whose Ni/Al alloy was doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pt, Cu, Ag, Au and Bi before activation and if the final activated Ni catalyst has an APS value lower than 25 μm, the remaining Al in the catalyst will be less leachable than that of a catalyst with a higher APS value. Similarly, if one produces an activated Ni catalyst with an APS lower than 25 μm that has been doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst, the remaining Al in the catalyst will be less leachable than that of a catalyst with a higher APS value. Likewise, if an activated Ni catalyst with an APS less than 25 μm is made from an Ni/Al alloy that contained one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi prior to activation and was subjected to the additional doping of one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst, the remaining Al in this resulting catalyst will also be less leachable than that of a catalyst with a higher APS value.

The results are even better when the APS value is lower than 20 μm. Hence, if one produces an activated Ni catalyst whose Ni/Al alloy was doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi before activation and if the final activated Ni catalyst has an APS value lower than 20 μm, the remaining Al in the catalyst will be less leachable than that of a catalyst with a higher APS value. In the same way, if one produces an activated Ni catalyst with an APS lower than 20 μm that has been doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst, the remaining Al in the catalyst will be less leachable than that of a catalyst with a higher APS value. Likewise, if an activated Ni catalyst with an APS less than 20 μm is made from an Ni/Al alloy that contained one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi prior to activation and was subjected to the additional doping of one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst, the remaining Al in this resulting catalyst will also be less leachable than that of a catalyst with a higher APS value.

Apparently the phase transformation that occurs during the formation of these smaller particles and their leaching behavior during alloy activation produces a more suitable catalyst that can take the full advantage the above mentioned doping elements with their corresponding methods for the avoidance of takovite during the reduction of nitro-compounds. The value of avoiding massive takovite formation was found to be much greater than the additional catalyst cost and surprisingly the lower takovite levels also improved the separation of the catalyst from the reaction mixture. As mentioned previously, the doping elements can be added to the alloy before activation, they could be adsorbed onto the catalyst during and/or after alloy activation or the they could be both incorporated into the alloy and adsorbed onto the catalyst during and/or after alloy activation.

It is possible to obtain catalysts of the preferred APS (less than 25 μm in some cases and less than 20 μm in others) by the application of the commonly used particle forming, grinding, sieving and classification (with either a liquid or gas medium; e.g., air, nitrogen, water and other appropriate mediums) technologies. Particle forming could take place during the cooling of the alloy, such as with alloys sprayed into and/or together with gas and/or liquid media. The formation of particles can also be achieved by rapidly cooling the allow against a cooled solid that may or may not be moving (e.g., spinning or swinging). Particle formation can also take place during the grinding step where ball mills, rod mills and classification mills that utilize either a liquid or gas carrier are being used. This grinding can be performed in one or more steps to achieve an appropriate particle size. When two or more steps are used, the initial grinding is commonly referred to the coarse grinding and additional grindings are referred to as the fine grinding steps. The invention of this patent can also be produced with mills that grind the alloy by suspending it in a flowing liquid and/or gas stream that experiences abrasive forces by going through a specially designed tube or reactor, by abruptly being forced against a fixed barrier (the walls of the tube or reactor may also be considered as a fixed barrier) and/or by being abruptly forced against a moving (e.g., spinning, swinging and other movements) barrier. In principle, the desired APS of this invention can be obtained by any commonly used grinding technologies known to those practicing the art of particle formation and grinding. One could also use a combination of these techniques such as is the case with a continuous ball or rod mill whose output is either sieved, gas classified or liquid classified with the oversized particles being feed back into the mill for further grinding. Another example that uses a combination of technologies would be the further grinding via mechanical methodologies of a rapidly cooled alloy (cooled with either a gas or with a liquid) that was already in powder form. Particle formation can also occur during the activation part of catalyst preparation, where the utilization of Al-rich phases in the alloy allows for a faster particle size reduction during activation. The Ni-rich phases can also be utilized to control the APS of the catalyst during activation. One can also use various doping methods and combinations of doping elements for the control of the APS during activation.

The powdered activated base metal catalysts (Raney-type catalysts) are typically used in either batch or continuous processes with stirred tank reactors. Batch processes are very flexible and under the right conditions, they are very economical for the hydrogenation of nitro-compounds to amines.

Another method involves the use of these powder catalysts in loop reactors where the reaction could occur in the vapor, trickle, aerosol or liquid phase. Loop, tube and stirred tank reactors can be used continuously for this process, where the nitro-compound is fed into the reactor at a rate in which it is immediately hydrogenated to completion or in some cases almost to completion when a second hydrogenation reactor (or even more) is used to hydrogenate the remaining amounts of the nitro-compound and its possible intermediates. During the continuous hydrogenation process, the same amount of the desired amine is removed from of the reaction system at the same rate as the nitro-compound is added to maintain the overall volume of the reaction medium in the reactor. In the case of loop and tube reactors, this reaction may be done in a circulation mode where the nitro-compound is introduced in one part of the circulating reaction stream and the finished product mixture is taken out of another part.

This reaction can take place in the presence of one or more solvents (for example but not limited to alcohols such as methanol and ethanol) or it can take place in the product mixture of the resulting amine and water. The advantages of using the product mixture for the reaction medium is that one does not need to buy the solvent and it does not need to be removed from the reaction mixture or possibly purified before being used again. Another option would be to perform the reaction in only the desired amine and to use a high enough reaction temperature so that the water is immediately distilled away from the reaction slurry and so that the desired amine remains in a liquid form. This is especially important for amines such as toluenediamine, where it needs to be kept in the molten state if it is to be used as the reaction medium without the assistance of solvents that maintain the liquid properties of the reaction slurry.

In general, the powder catalysts of this invention can be used in any reaction system and in any reaction process that is suitable for the hydrogenation of nitro-compounds to amines that utilize powder catalysts.

This invention includes the process for the hydrogenation of nitro-compounds with an activated Ni catalyst whose Ni/Al alloy contained one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pt, Cu, Ag, Au and Bi before activation while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process of this embodiment for the hydrogenation of nitro-compounds is with an activated Ni catalyst made from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Fe, Ru, Co, Ir, Pt, Cu and Ag before activation while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

A further variation of this invention involves the hydrogenation of nitro-compounds with an activated Ni catalyst that has an APS less than 25 μm that was doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process for the hydrogenation of nitro-compounds from this embodiment uses an activated Ni catalyst that has an APS less than 25 μm and is doped by one or more elements from the list of Mg, Ti, V, Cr, Fe, Ru, Co, Ir, Ni, Cu and Ag by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

This invention also includes a process for the hydrogenation of nitro-compounds with an activated Ni catalyst whose Ni/Al alloy was doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi before activation followed by doping the final activated Ni catalyst with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process for the hydrogenation of nitro-compounds of this embodiment utilizes an activated Ni catalyst made from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Pd, Pt, Cu and Ag before activation followed by doping the final activated Ni catalyst with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Ni, Pd, Pt, Cu and Ag by its/their adsorption onto the surface of the catalyst while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

This invention also covers the hydrogenation of nitro-compounds with an activated Ni catalyst made from a Ni/Al alloy that contained one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi before activation while keeping the average particle size (APS) of the final activated catalyst less than 20 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred hydrogenation process of nitro-compounds of this embodiment uses an activated Ni catalyst made from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Pd, Pt, Cu and Ag before activation while keeping the average particle size (APS) of the final activated catalyst less than 20 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

A further part of this invention includes a process for the hydrogenation of nitro-compounds with an activated Ni catalyst that has an APS less than 20 μm and is doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process for the hydrogenation of nitro-compounds of this embodiment uses an activated Ni catalyst that has an APS less than 20 μm and is doped by one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Ni, Pd, Pt, Cu and Ag by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

This invention includes the process for the hydrogenation of nitrated aromatics with an activated Ni catalyst whose Ni/Al alloy contained one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pt, Cu, Ag, Au and Bi before activation while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process of this embodiment for the hydrogenation of nitrated aromatics is with an activated Ni catalyst made from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Fe, Ru, Co, Ir, Pt, Cu and Ag before activation while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

A further variation of this invention involves the hydrogenation of nitrated aromatics with an activated Ni catalyst that has an APS less than 25 μm that was doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process for the hydrogenation of nitrated aromatics from this embodiment uses an activated Ni catalyst that has an APS less than 25 μm and is doped by one or more elements from the list of Mg, Ti, V, Cr, Fe, Ru, Co, Ir, Ni, Cu and Ag by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

This invention also includes a process for the hydrogenation of nitrated aromatics with an activated Ni catalyst whose Ni/Al alloy was doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi before activation followed by doping the final activated Ni catalyst with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process for the hydrogenation of nitrated aromatics of this embodiment utilizes an activated Ni catalyst made from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Pd, Pt, Cu and Ag before activation followed by doping the final activated Ni catalyst with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Ni, Pd, Pt, Cu and Ag by its/their adsorption onto the surface of the catalyst while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

This invention also covers the hydrogenation of nitrated aromatics with an activated Ni catalyst made from a Ni/Al alloy that contained one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi before activation while keeping the average particle size (APS) of the final activated catalyst less than 20 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred hydrogenation process of nitrated aromatics of this embodiment uses an activated Ni catalyst made from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Pd, Pt, Cu and Ag before activation while keeping the average particle size (APS) of the final activated catalyst less than 20 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

A further part of this invention includes a process for the hydrogenation of nitrated aromatics with an activated Ni catalyst that has an APS less than 20 μm and is doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process for the hydrogenation of nitrated aromatics of this embodiment uses an activated Ni catalyst that has an APS less than 20 μm and is doped by one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Ni, Pd, Pt, Cu and Ag by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

This invention includes the process for the continuous hydrogenation of nitrated aromatics with an activated Ni catalyst whose Ni/Al alloy contained one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pt, Cu, Ag, Au and Bi before activation while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process of this embodiment for the continuous hydrogenation of nitrated aromatics is with an activated Ni catalyst made from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Fe, Ru, Co, Ir, Pt, Cu and Ag before activation while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

A further variation of this invention involves the continuous hydrogenation of nitrated aromatics with an activated Ni catalyst that has an APS less than 25 μm that was doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process for the continuous hydrogenation of nitrated aromatics from this embodiment uses an activated Ni catalyst that has an APS less than 25 μm and is doped by one or more elements from the list of Mg, Ti, V, Cr, Fe, Ru, Co, Ir, Ni, Cu and Ag by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

This invention also includes a process for the continuous hydrogenation of nitrated aromatics with an activated Ni catalyst whose Ni/Al alloy was doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi before activation followed by doping the final activated Ni catalyst with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process for the continuous hydrogenation of nitrated aromatics of this embodiment utilizes an activated Ni catalyst made from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Pd, Pt, Cu and Ag before activation followed by doping the final activated Ni catalyst with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Ni, Pd, Pt, Cu and Ag by its/their adsorption onto the surface of the catalyst while keeping the average particle size (APS) of the final activated catalyst less than 25 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

This invention also covers the continuous hydrogenation of nitrated aromatics with an activated Ni catalyst made from a Ni/Al alloy that contained one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pd, Pt, Cu, Ag, Au and Bi before activation while keeping the average particle size (APS) of the final activated catalyst less than 20 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred continuous hydrogenation process of nitrated aromatics of this embodiment uses an activated Ni catalyst made from a Ni/Al alloy that was doped with one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Pd, Pt, Cu and Ag before activation while keeping the average particle size (APS) of the final activated catalyst less than 20 μm whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

A further part of this invention includes a process for the continuous hydrogenation of nitrated aromatics with an activated Ni catalyst that has an APS less than 20 μm and is doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au and Bi by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %. The preferred process for the continuous hydrogenation of nitrated aromatics of this embodiment uses an activated Ni catalyst that has an APS less than 20 μm and is doped by one or more elements from the list of Mg, Ti, V, Cr, Mo, Fe, Ru, Co, Ir, Ni, Pd, Pt, Cu and Ag by its/their adsorption onto the surface of the catalyst whereas, the doping levels in the final catalyst can range from 0.01 wt % to 10 wt % for each doping element and the Al content in the final catalyst ranges from 0.05 wt % to 10 wt %.

There are many types of nitro-compound hydrogenations performed in industry. One of the more commercially interesting and technically challenging is the hydrogenation of dinitrotoluene (DNT) to toluenediamine (TDA). This hydrogenation is performed with activated Ni catalysts at temperatures ranging from room temperature to 210° C. and pressures ranging from atmospheric pressure to 200 bar. The preferred reaction conditions are within the ranges of 50° to 180° C. and 3 to 80 bar. This reaction can be performed in an excess of hydrogen or under a stoichiometric amount of hydrogen.

In U.S. Pat. No. 6,423,872, the reaction conditions for the continuous hydrogenation of DNT were 20 bar hydrogen at 150° C. with 0.7 grams of activated Ni catalyst and a DNT feed that kept the level of DNT below 1000 ppm during this hydrogenation. In U.S. Pat. No. 3,935,264, the hydrogenation of DNT was performed with methanol as a solvent under the pressure of 28.5 bar hydrogen and 120° C. over the activated Ni catalyst.

Recently in U.S. Pat. No. 6,005,143, it was found that one could achieve satisfactory results for the hydrogenation of DNT to TDA over a Ni/Pd catalyst supported on a monolith in the presence of methanol with 16 bar hydrogen and temperatures ranging from 135 to 155° C.

Typically fixed bed hydrogenation processes require higher hydrogen pressures than their slurry phase counterparts, indicating that pressures of ˜16 Bar should also be suitable for the reactions performed here. U.S. Pat. No. 4,224,249 also showed this to be true as a Raney-type Ni catalyst was successfully used at 130° C. and 160 psig (12 bar) for the hydrogenation of dinitrotoluene (DNT) in both the batch and the incremental feed modes of operation. The incremental feed mode of operation was used to simulate the conditions in which DNT is continuously hydrogenated on a industrial scale.

The hydrogenation of nitro-compounds can take place in the vapor, slurry, trickle, aerosol and/or liquid phase. The reaction could be performed as a batch process or it could be performed as a continuous process. The continuous processes may involve, but they are not limited to, a type of circulation process. This invention also includes a continuous process where the nitro-compound is added at a rate that is the same or slower than the rate of hydrogenation, so that the concentration of the nitro-compound is kept to a very low level. The feeding rate of the nitro-compound may be so low that the level of the nitro-compound is 1000 ppm or lower. This invention also includes the use of the previously mentioned catalyst of this invention in a continuous process that utilizes a second hydrogenation reactor (or more) to hydrogenate any nitro-compounds and/or intermediates that were remaining from the hydrogenation in the first hydrogenation reactor.

The nitro-compound hydrogenation of this invention may take place in the presence of the neat nitro-compound, at high concentrations of the reactant, at very low concentrations of the reactant and/or in the presence of the product mixture that would be acting like a solvent. This hydrogenation may also take place in the presence of practically only the desired amine if the water is removed in a satisfactory method (e.g., distillation) during the reaction. The nitro-compound hydrogenation of this invention may take place in the presence of a solvent. The reactor type could be, but is not limited to, a stirred tank reactor, a continuous stirred tank reactor, a loop reactor or a tube reactor. This nitro-compound hydrogenation may occur between atmospheric pressure and 200 bars of hydrogen and the temperature can range from ˜10° C. to 210° C.

This invention encompasses the hydrogenation of nitrated aromatics and this may occur either as a batch or a continuous process over the above mentioned catalysts. This invention also includes the hydrogenation of DNT to TDA as either a batch process or a continuous process with the above described catalysts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: FIG. 1 is a graph showing DNT pulse hydrogenation data for CE1, CE2, CE3, E2, E3 and E4.

FIG. 1: FIG. 2 is a graph showing DNT pulse hydrogenation data for CE1, CE2, CE3, E5, E6, E7, E8, E9, E10, E11, E12, E13 and E14.

APPLICATION EXAMPLE 1

The Pulse Hydrogenation of dinitrotoluene (DNT) to toluenediamine (TDA).

DNT is typically hydrogenated in an industrial setting via a continuous mode, where the DNT feed rate is slow enough to keep its concentration low enough so that it doesn't poison the catalyst or become a safety hazard. This means that the hydrogenation rate will be dependent of the DNT feed rate. The goal of our pulse hydrogenation method was to keep the DNT concentration low enough so that it would be comparable to the industrial setting while measuring the activity of the catalyst. We were able to do so by pulsing in the DNT feed at a rate that was slightly faster than the rate of hydrogenation so that we could measure catalyst activity while keeping the time of the slight excess of DNT to a minimum. It was also decided to use the reaction pressure and temperature conditions similar to those described in U.S. Pat. Nos. 4,224,249, 6,423,872 and 6,005,143.

The pulse hydrogenation method was started by placing 150 or 300 milligrams of catalyst, 101 grams of TDA and 59 grams of water (the reaction's stoichiometric TDA-to-water ratio) into a 500 ml autoclave. The autoclave was then closed, purged with nitrogen 3 times, purged with hydrogen 3 times and heated to the reaction temperature of 140° C. over a period of 20 minutes while the reactor was stirring at 300 rpm and kept under 5 bar hydrogen. Once the autoclave reached 140° C., the hydrogen pressure was adjusted to 15 bar hydrogen and the stirring rate was increased to 1700 rpm. The reaction was then started by pulsing 4 milliliters of molten DNT into the reactor over 30 seconds with an HPLC pump. The HPLC pump head, the DNT reservoir and all the stainless tubing used for the transport of DNT was kept at 95° C. to keep the DNT molten. A Büchi hydrogen press flow controller (bpc 9901) was used to monitor the hydrogen consumption and once the reaction stopped to consume hydrogen, another pulse of DNT was introduced at the same feed rate. This procedure was continued until a maximum of 45 pulses had been introduced. The data from these hydrogenations can be seen in graph 1, graph 2 and in data tables 3 to 19.

APPLICATION EXAMPLE 2

The Batch Hydrogenation of Nitrobenzene to Aniline.

The low pressure hydrogenation of nitrobenzene was carried out over 1.5 grams of catalyst in 110 ml of a 9.1 wt % nitrobenzene ethanolic solution at 25° C. and atmospheric pressure. A baffled glass reactor outfitted with a bubbling stirrer spinning at 2000 rpm was used for these hydrogenations. The results of these hydrogenations are listed in table 1.

TABLE 1 The batch nitrobenzene hydrogenation data. Nitrobenzene Activity Catalyst ml H₂/min/gram catalyst Comparative Example 1 61 Comparative Example 2 49 Example 1 97 Example 2 108 Example 3 77 Example 4 70 Example 5 75 Example 6 96 Example 7 92 Example 12 74 Example 14 80

APPLICATION EXAMPLE 3

The Determination of the Catalyst's Ability to Form Nickel Aluminates (e.g., Takovite).

U.S. Pat. No. 6,423,872 describes a method for the determination of the catalyst's ability to form nickel aluminates (e.g., takovite). This method involved putting the catalyst together with TDA at the temperature of 150° C. for 1 month. The tube was then opened and the catalyst was examined by X-Ray diffraction. It was found that the compound built up on the catalyst was takovite and its structure was shown by X-Ray diffraction to be the same as that of the deposits observed on the walls of an industrial DNT hydrogenation reactor and its peripheral equipment.

We performed a similar test for our studies here.

To determine the catalyst's ability to form takovite, 0.2 grams of the catalyst was placed together with 3.5 grams of a 63 wt % TDA and 37 wt % water mixture in a sealed tube for 3 weeks at 150° C. After the 3 weeks, the catalyst was removed and its takovite residues were analyzed by X-Ray diffraction. The takovite peak heights were then measured at the 12, 24, 35, 40 and 47 ° 2 theta positions. The nickel peak height at the 52 ° 2 theta position was also measured and it was the ratios of the individual takovite peak heights to the nickel peak height that was used to compare the different catalysts to each other. The relative ratios for these ° 2 theta positions were consistent enough for the different catalysts so that it was possible to consider using the ratio of the sum of the takovite peak heights for the 12, 24, 35, 40 and 47 ° 2 Theta positions to the nickel peak height at 52 ° 2 theta for this determination.

The data from these experiments are shown in table 2 and the catalysts with the higher takovite formation had the higher takovite-to-Ni peak height ratios. By comparing the catalysts of the same Al content to each other, one can see that the embodiments of this patent lead to lower levels of takovite formation. Only comparative example 1 (CE1) formed a hard version of takovite and the others examples described here only formed soft takovite, if they formed takovite at all.

TABLE 2 The x-ray diffraction data for the takovite deposits on the activated nickel catalysts. Takovite peak heights (mm) at Ni at Ratio of takovite peak heights to Example the below listed °2 Θ positions 52 the Ni peak peak height number 12 24 35 40 47 °2Θ 12 24 35 40 47 Sum CE1 47 33 22 26 22.5 3.0 15.7 11 7.3 8.7 7.5 50.2 CE2 19.5 12.0 12.0 8.0 7.0 12.5 1.6 1.0 1.0 0.6 0.6 4.7 CE3 54 31.5 25.5 18.5 17 7.0 7.7 4.5 3.6 2.6 2.4 20.9 E1 48.5 28 28 21 19 7.0 6.9 4.0 4.0 3.0 2.7 20.6 E2 35 20 18.5 13.5 11.5 9.0 3.9 2.2 2.1 1.5 1.3 10.9 E3 34 21.5 20 15 13 9.0 3.8 2.4 2.2 1.7 1.4 11.5 E4 26.5 15.5 14.5 10 9.0 11 2.4 1.4 1.3 0.9 0.8 6.9 E5 15 10 10 7.5 6.0 13 1.2 0.8 0.8 0.6 0.5 3.7 E6 13 10 10 7.5 6.5 11 1.2 0.9 0.9 0.7 0.6 4.3 E7 20 13 12.5 9 8 11.2 1.8 1.2 1.1 0.8 0.7 5.6 E8 13 9.0 8.0 5.5 5.0 14 0.9 0.6 0.6 0.4 0.4 2.9 E9 12 8.0 8.0 5.0 4.5 15 0.8 0.5 0.5 0.3 0.3 2.5 E10 0.0 0.0 0.0 0.0 0.0 14 0.0 0.0 0.0 0.0 0.0 0.0 E11 23 12.5 12 8.0 7.0 12.5 1.8 1.0 1.0 0.6 0.6 5.0 E12 24 13 13 9.0 8.0 12 2.0 1.1 1.1 0.8 0.7 5.6 E13 18.5 10.5 11 7.0 6.0 12.5 1.5 0.8 0.9 0.6 0.5 4.2 E14 29 12 12 12 10.2 11 2.6 1.1 1.1 1.1 0.9 6.8 E15 0.0 0.0 0.0 0.0 0.0 13 0.0 0.0 0.0 0.0 0.0 0.0

COMPARATIVE EXAMPLE 1

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in activated Ni catalyst containing 8.8 wt % Al, 2.5 wt % Cr and 2 wt % Fe with an average particle size value of 35 μm was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 50.2. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 61 ml H₂/min/gram of catalyst and additional information can be seen in table 1. As described in application example 1, 150 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 90% toluenediamine and the activity data points are given below in table 3 and graph 1.

TABLE 3 The dinitrotoluene hydrogenation data for comparative example 1. Hydrogenation Activity grams TDA yielded ml H₂ per minute per gram of per gram of catalyst catalyst 15.5 1719 39.4 1258 59.1 1082 81.2 775 99.7 692 116.4 591 137.9 515

COMPARATIVE EXAMPLE 2

An alloy containing Ni, Al and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 4 wt % Al, and 0.2 wt % Fe with an average particle size value of 28 μm was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 4.7. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 49 ml H₂/min/gram of catalyst and additional information can be seen in table 1. As described in application example 1, 150 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99% toluenediamine and the activity data points are given below in table 4 and graph 1.

TABLE 4 The dinitrotoluene hydrogenation data for comparative example 2. grams TDA yielded per gram of Hydrogenation Activity ml H₂ catalyst per minute per gram of catalyst 20 1575 31 1620 44 1842 59 1848 77 1893 96 1796 116 1644 137 1567 158 1520 179 1541 200 1586 222 1439 243 1488 265 1533 288 1527 309 1456 333 1436 354 1469 375 1480 397 1422 418 1447 440 1424 462 1393 484 1385 506 1370 528 1341 549 1259 571 1283 593 1183

COMPARATIVE EXAMPLE 3

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 6.3 wt % Al, 1.9 wt % Cr and 0.8 wt % Fe with an APS value of 29 μm was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 20.9. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. As described in application example 1, 150 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99% toluenediamine and the activity data points are given below in table 5 and graph 1.

TABLE 5 The dinitrotoluene hydrogenation data for comparative example 3. grams TDA yielded per gram of Hydrogenation Activity ml H₂ catalyst per minute per gram of catalyst 6 3154 18 3447 34 3587 51 3440 71 3175 89 3210 111 2924 129 3057 151 2808 172 2607 193 2521 214 2350 237 2273 258 2223 280 2142 302 2070 324 2016 346 1764 367 1788 389 1618 411 1677 432 1591 453 1486 473 1424 494 1380 514 1292 532 1216 552 1187

EXAMPLE 1

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 7.2 wt % Al, 1.8 wt % Cr and 0.7 wt % Fe with an APS value of 22 μm was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 20.6. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. The only differences between CE3 and E1 is that E1 has ˜0.9% more Al on an absolute basis (14% more Al on a relative basis) and E1 has a APS lower than 25 μm and CE3 doesn't. In spite of the higher Al content, E1 forms less takovite than CE3 and this is due to the lower APS. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 97 ml H₂/min/gram of catalyst and additional information can be seen in table 1.

EXAMPLE 2

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 5.4 wt % Al, 1.7 wt % Cr and 0.3 wt % Fe with an APS value of 16 μm was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 10.9. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 108 ml H₂/min/gram of catalyst and additional information can be seen in table 1. As described in application example 1, 150 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 6 and graph 1.

TABLE 6 The dinitrotoluene hydrogenation data for example 2. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 21 3500 43 3070 75 3344 97 3020 120 2841 143 2933 165 2863 188 2561 209 2720 232 2823 254 2828 276 2692 299 2692 322 2627 344 2581 367 2593 389 2353 411 2532 434 2550 457 2590 480 2433 502 2542 526 2424 549 2233 572 2222 595 2262 616 2151 639 2122

EXAMPLE 3

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 5.7 wt % Al, 1.5 wt % Cr and 0.2 wt % Fe with an APS value of 24 μm was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 11.5. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 77 ml H₂/min/gram of catalyst and additional information can be seen in table 1. As described in application example 1, 150 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 7 and graph 1.

TABLE 7 The dinitrotoluene hydrogenation data for example 3. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 17 3838 27 3589 47 4115 66 4039 85 3848 105 4071 126 3924 147 3687 168 3637 189 3459 210 3353 230 3410 251 3248 273 3274 294 2971 316 2872 337 3002 359 2952 381 2803 404 2797 425 2698 448 2661 470 2627 493 2515 515 2531 538 2451 561 2394 583 2315 605 2259 628 2254 651 2237 673 2012 697 1922 719 1810 742 1803 764 1747 787 1660

EXAMPLE 4

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 4.63 wt % Al, 0.6 wt % Cr and 0.2 wt % Fe with an APS value of 22 μm was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 6.9. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 70 ml H₂/min/gram of catalyst and additional information can be seen in table 1. As described in application example 1, 150 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 8 and graph 1.

TABLE 8 The dinitrotoluene hydrogenation data for example 4. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 20 2900 31 2710 43 2826 57 3021 73 3311 90 2979 108 3211 128 3204 147 3109 168 3124 188 3086 209 3017 230 3037 250 2892 271 2918 292 2825 313 2813 333 2721 354 2807 375 2635 395 2569 416 2606 437 2474 458 2542 478 2297 498 2319 518 2298 539 2220 559 2231 579 2193 598 2159 618 2082 638 1934 659 1986 678 1984 699 1955 718 1867 739 1877

EXAMPLE 5

An alloy containing Ni, Al, Cr, Cu and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 3.9 wt % Al, 0.72% Cr, 0.07% Cu and 0.26 wt % Fe. This catalyst had an APS value of 22 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 3.7. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 17 and graph 2

TABLE 9 The dinitrotoluene hydrogenation data for example 5. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 9 2928 15 3135 22 2904 31 3289 40 3330 49 3279 59 3404 69 3533 79 3350 90 3145 100 3169 111 3333 120 3750 131 3350 141 3385 151 3179 162 3518 172 3331 182 3245 193 3518 203 3594 214 3402 225 3349 235 3385 245 3422 256 3279 266 3367 277 3195 288 3212 298 3232 307 3064 318 3268 328 3286 339 3094 350 2990 350 2924 360 2704 371 2815 392 2535 402 2471

EXAMPLE 6

An alloy containing Ni, Al, Cr, Cu and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 4.3 wt % Al, 1.53% Cr, 0.12% Cu and 0.25 wt % Fe. This catalyst had an APS value of 22 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 4.3. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 96 ml H₂/min/gram of catalyst (please see table 1). As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 18 and graph 2

TABLE 10 The dinitrotoluene hydrogenation data for example 6. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 21 3382 44 2829 66 2775 89 2857 112 2818 135 2613 158 2535 181 2326 204 2164 227 2146 250 2236 273 2205 297 2185 320 2133 343 2105 367 2078 390 2040 413 2081

EXAMPLE 7

An alloy containing Ni, Al, Cr, Cu and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 4.5 wt % Al, 1.35% Cr, 0.17% Cu and 0.26 wt % Fe. This catalyst had an APS value of 20 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 5.6. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 92 ml H₂/min/gram of catalyst (please see table 1). As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 20 and graph 2

TABLE 11 The dinitrotoluene hydrogenation data for example 7. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 22 3945 43 3608 65 3518 87 3380 110 3186 132 3038 154 3000 177 2835 200 2775 223 2585 245 2574 268 2341 290 2491 314 2262 336 2280 360 2181 383 1986 405 1778 429 1707

EXAMPLE 8

An alloy containing Ni, Al and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 3.79 wt % Al, and 0.23 wt % Fe. This catalyst had an APS value of 20 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 2.9. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 21 and graph 2

TABLE 12 The dinitrotoluene hydrogenation data for example 8. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 10 1943 19 2330 29 2328 38 2288 49 2409 59 2366 69 2318 80 2552 90 2478 101 2264 112 2457 123 2399 133 2432 144 2334 155 2398 165 2408 176 2350 187 2223 198 2311 209 2149 220 2319 230 2216 241 2202 252 2155 263 2097 274 2115 284 2182 295 2148 306 2059 317 2090 328 2042 338 2036 349 2018 360 1919 371 1940 381 1837

EXAMPLE 9

An alloy containing Ni, Al and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 3.87 wt % Al and 0.22 wt % Fe that was doped with an aqueous solution of an ammonium molybdate salt to the final Mo content of 0.11 wt % Mo. This catalyst had an APS value of 17 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 2.5. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 22 and graph 2

TABLE 13 The dinitrotoluene hydrogenation data for example 9. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 9 2449 18 2441 28 2572 39 2590 49 2560 60 2617 71 2597 81 2778 93 2633 104 2747 115 2694 126 2725 137 2594 148 2546 159 2510 170 2546 181 2688 193 2535 204 2500 215 2546 226 2483 237 2556 249 2518 260 2449 271 2389 283 2483 294 2372 305 2368 316 2416 328 2372 339 2334 350 2305 362 2228 373 2119 384 2161 396 2117

EXAMPLE 10

An alloy containing Ni, Al and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 3.81 wt % Al and 0.21 wt % Fe that was doped with an aqueous solution of CuSO₄ to the final Cu content of 0.09 wt % Cu. This catalyst had an APS value of 20 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 0.0. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 23 and graph 2

TABLE 14 The dinitrotoluene hydrogenation data for example 10. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 10 2369 18 2384 25 2521 35 2467 45 2460 55 2348 66 2365 76 2536 87 2419 98 2614 110 2730 121 2676 133 2560 144 2544 155 2432 167 2418 178 2526 190 2483 201 2517 213 2459 224 2475 236 2264 247 2400 259 2271 270 2299 282 2320 293 2306 305 2210 316 2177 327 2223 339 2230 350 2210 362 2115 374 2055 385 2051 396 1975

EXAMPLE 11

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 4.07 wt % Al, 0.73% Cr and 0.28 wt % Fe that was doped with an aqueous solution of an ammonium molybdate salt to the final Mo content of 0.1 wt % Mo. This catalyst had an APS value of 23 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 5.0. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 24 and graph 2

TABLE 15 The dinitrotoluene hydrogenation data for example 11. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 11 3004 21 3413 29 3020 39 3130 49 3724 60 3407 71 3603 82 3761 93 3983 105 3983 116 3815 128 3652 139 3876 151 3679 162 3564 174 3547 185 3876 197 3356 208 3795 220 3860 231 3417 243 3582 254 3519 266 3553 277 3588 289 3326 301 3433 312 3403 323 3502 335 3311 346 3310 358 3162 369 3170 381 2968 393 3091 404 3028

EXAMPLE 12

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 4.11 wt % Al, 0.71% Cr and 0.27 wt % Fe. This catalyst had an APS value of 22 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 5.6. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 74 ml H₂/min/gram of catalyst (please see table 1). As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 25 and graph 2

TABLE 16 The dinitrotoluene hydrogenation data for example 12. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 11 2803 20 3303 26 3030 31 3181 36 3115 42 3015 49 2983 56 3322 64 3174 73 3472 81 3383 90 3136 99 3067 109 3125 118 3142 127 3341 136 3421 145 3303 154 3181 163 3011 173 3101 182 3147 191 2995 200 2949 210 3067 219 2964 228 2876 238 2903 255 2925 265 2903 275 3005 284 3027 293 2964 293 2964 302 2848 311 2794 320 2808 330 2905 339 2820 348 2784

EXAMPLE 13

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 4.1 wt % Al, 0.72% Cr and 0.28 wt % Fe that was doped with an aqueous solution of CuSO₄ to the final Cu content of 0.11 wt % Cu. This catalyst had an APS value of 23 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 4.2. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 26 and graph 2

TABLE 17 The dinitrotoluene hydrogenation data for example 13. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 9 2863 16 2891 24 3370 32 3427 40 3399 49 3277 58 3469 67 3619 77 3469 86 3650 95 3347 105 3224 114 3543 124 3257 133 3257 142 3091 152 3075 161 2992 171 3066 180 3045 189 2932 199 2844 208 2792 218 3166 228 2970 237 2985 246 3064 256 2869 265 3097 275 3029 285 2805 294 2983 304 2741 313 2705 322 2792 332 2766 341 2589 351 2927 361 2844 370 2683

EXAMPLE 14

An alloy containing Ni, Al, Cr and Fe was activated in an aqueous 20 wt.-% NaOH suspension between 100 and 110° C. resulting in an activated Ni catalyst containing 4.53 wt % Al, 1.51% Cr and 0.29 wt % Fe that was doped with an aqueous solution of an ammonium molybdate salt to the final Mo content of 0.13 wt % Mo. This catalyst had an APS value of 23 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 6.8. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2. This catalyst was used for the batch hydrogenation of nitrobenzene to aniline as described in application example 2. The nitrobenzene hydrogenation activity of this catalyst was found to be 80 ml H₂/min/gram of catalyst (please see table 1). As described in application example 1, 300 milligrams of this catalyst were used for the pulse hydrogenation of dinitrotolunene to toluenediamine. The selectivity of this reaction was greater than 99.5% toluenediamine and the activity data points are given below in table 27 and graph 2

TABLE 18 The dinitrotoluene hydrogenation data for example 14. Hydrogenation Activity grams TDA yielded per gram of ml H₂ per minute per gram of catalyst catalyst 9 3440 15 3046 20 3130 28 3344 37 3602 46 3627 56 3912 66 3888 76 3725 85 3535 95 3471 105 3398 114 3804 125 3575 134 3649 144 3527 155 3490 164 3592 174 3763 184 3548 194 3583 204 3174 214 3202 223 3291 233 3308 243 3344 253 3381 262 3420 271 3382 281 3079 290 3306 300 3119 309 3104 318 2924 327 3168 337 3219 346 3015 355 3071 365 2853 373 2867

EXAMPLE 15

An alloy containing Ni, Al and Fe was activated in an aqueous 20 wt.-% NaOH suspension in the presence of a fine Cr powder between 100 and 110° C. resulting in an activated Ni catalyst containing 3.92 wt % Al, 0.42% Cr and 0.22 wt % Fe. This catalyst had an APS value of 20 μm and was tested for the formation of takovite as described in application example 3. The ratio of the sum of the takovite x-ray diffraction peak heights at 12, 24, 35, 40 and 47 ° 2 theta to the nickel x-ray diffraction peak height at 52 ° 2 theta was found to be 0.0. The individual takovite-to-nickel ratios of the x-ray peaks at 12, 24, 35, 40 and 47 ° 2 theta can be seen in table 2.

The results shown in the above examples clearly demonstrate that the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned as well as those inherent therein. While increasing the Al content of the catalyst enhances its activity, it can also increase the amount of takovite produced during the hydrogenation of nitro-compounds such as dinitrotoluene. Hence in the past, one had to select between either higher activity and the increased presence of takovite, or less catalyst activity (with lower Al contents) and less takovite. Stabilizing the Al in the catalyst by the inventions of this patent will allow the practitioner of nitro-compound hydrogenation to have both high activity and less takovite. Application example 3 describes how we determined the ability of the catalyst to form takovite and the ratio of the sum of takovite ° 2 theta peak heights to the Ni 52 ° 2 theta peak height normalizes this measurement with respect to the XRD measured Ni quantity and this value is referred to here as the takovite propensity. To compare the takovite propensities of catalysts containing different Al contents one should then divide the takovite propensity by the wt. % Al to determine the relative amount of Al in the catalyst that is leachable with a amino compounds such as toluenediamine (TDA) to form takovite. Another aspect is the activity of the catalyst. If the catalyst is highly active, one would need less of this catalyst to form the same amount of the desired amine. Hence the most important aspect of the takovite propensity is the relative amount of takovite formed with respect to catalyst activity and the wt. % Al. Since the dinitrotoluene hydrogenation experiments measured here go to a minimum of ˜350 grams of toluenediamine produced per gram of catalyst, we took the average activity up to 350 grams of toluenediamine per gram of catalyst as the standard comparison for our catalysts and this together with the relative amount of takovite formed with respect to activity and Al content are listed in table 13. One can see from the data that the proper selection of the doping methods, the doping elements and the APS can surprisingly lead to a catalyst that has a high activity and forms a low amount of takovite with respect to activity and Al content.

TABLE 28 The comparison of takovite formation with respect to Al content and pulse dinitrotoluene hydrogenation activity. Relative amount of Takovite Average with Activity respect to 350 g Ratio of Relative to wt % Al Doping APS TDA per Sum Takovite:Ni Activity and Catalyst elements μm g cat wt. % Al Takovite:Ni to wt. % Al to CE2 Activity CE1 Cr, Fe 35 379 8 50.2 6.27 0.24 26.49 CE2 Fe 26 1599 4 4.7 1.17 1.00 1.17 CE3 Cr, Fe 27 2709 6 20.9 3.49 1.69 2.06 E2 Cr, Fe 16 2873 5.4 10.9 2.03 1.80 1.13 E3 Cr, Fe 24 3516 5.7 11.5 2.02 2.20 0.92 E4 Cr, Fe 22 2974 4.63 6.9 1.48 1.86 0.80 E5 Cr, Fe, 22 3292 3.9 3.7 0.96 2.06 0.46 Cu E6 Cr, Fe, 22 2487 4.3 4.3 0.99 1.56 0.64 Cu E7 Cr, Fe, 20 2875 4.5 5.6 1.24 1.80 0.69 Cu E8 Fe 20 2255 3.79 2.9 0.76 1.41 0.54 E9 Fe, Mo 17 2528 3.87 2.5 0.65 1.58 0.41 E10 Fe, Cu 20 2413 3.81 0.0 0.00 1.51 0.00 E11 Cr, Fe, 23 3548 4.07 5.0 1.23 2.22 0.55 Mo E12 Cr, Fe 22 3056 4.11 5.6 1.36 1.91 0.71 E13 Cr, Fe, 23 3089 4.1 4.2 1.02 1.93 0.53 Cu E14 Cr, Fe, 23 3408 4.53 6.8 1.50 2.13 0.70 Mo

While modification may be made by those skilled in the art, such modifications are encompassed within the spirit of the present invention as defined by the disclosure and the claims. 

The invention claimed is:
 1. An activated catalyst comprising: a) a Ni/Al alloy comprising Fe: b) a doping element selected from the group consisting of Mo and Cu adsorbed onto the surface of said activated catalyst; and wherein: i) said activated catalyst is in the form of particles with an average particle size (APS) of less than 25 μm; ii) each doping element in said activated catalyst is present at 0.01 wt % to 10 wt %; and iii) Al is present in said activated catalyst at 0.05 wt% to 10 wt %.
 2. The activated catalyst of claim 1, wherein said Ni/Al alloy further comprises Cr or both Cr and Cu.
 3. The activated catalyst of claim 1, wherein said APS is less than 20 μm.
 4. The activated catalyst of claim 1, wherein the Ni/Al alloy is doped with Fe or a combination of Cr and Fe and has the doping element Mo adsorbed onto its surface.
 5. The activated catalyst of claim 4, wherein said APS is less than 20 μm.
 6. The activated catalyst of claim 1, wherein the Ni/Al alloy is doped with Fe or a combination of Cr and Fe and has the doping element Cu adsorbed onto its surface.
 7. The activated catalyst of claim 6, wherein said APS is less than 20 μm.
 8. A method for the hydrogenation of a nitro-compound, comprising reacting said nitro-compound with hydrogen in the presence of the activated catalyst of claim
 1. 9. The method of claim 8, wherein said nitro-compound is a nitrated aromatic.
 10. The method of claim 9, wherein the hydrogenation is carried out continuously.
 11. The method of claim 8 wherein the APS of said activated catalyst is less than 20 μm.
 12. The method of claim 8, wherein the Ni/Al alloy of said activated catalyst is doped with Fe or a combination of Cr and Fe and has the doping element Mo adsorbed onto its surface.
 13. The method of claim 12, wherein said nitro-compound is a nitrated aromatic.
 14. The method of claim 13, wherein the hydrogenation is carried out continuously.
 15. The method of claim 12, wherein the APS of said activated catalyst is less than 20 μm.
 16. The method of claim 15, wherein said nitro-compound is a nitrated aromatic.
 17. The method of claim 8, wherein the Ni/Al alloy of said activated catalyst is doped with Fe or a combination of Cr and Fe and has the doping element Cu adsorbed onto its surface.
 18. The method of claim 17, wherein said nitro-compound is a nitrated aromatic.
 19. The method of claim 18, wherein the hydrogenation is carried out continuously.
 20. The method of claim 17, wherein the APS of said activated catalyst is less than 20 μm.
 21. The method of claim 20, wherein said nitro-compound is a nitrated aromatic. 